判断对称二叉树

mirror

public boolean isMirror(node left, node right){

    if(null == right && null == left){
               return true;
    }else if( null == right || null == left ){
               return false;
    }

   if(right.val != left.val)
             return false;
   
   return isMirror(left.left, right.right) && isMirror(left.right, right.left)
}